The present invention generally relates to a readily portable imaging system for use in the field and, more particularly, to an electronic camera and electronic printer housed and readily connectable with respect to each other in the field, and wherein the electronic printer comprises a film unit drive assembly that advances the film unit (self-developing type) past a stationary print head for emitting consecutive lines of image data on the film unit to effect progressive exposure on the film unit simultaneously as a fluid spread system spreads the processing fluid over the film unit to effect processing of exposed portions of the film unit.
There are numerous types of drive assemblies for photographic printers. One such drive assembly is described in Johnson, U.S. patent application Ser. No. 08/931,570 entitled xe2x80x9cPrint Head Drive Assemblyxe2x80x9d of which is a commonly owned co-pending Patent Application. Johnson discloses a print head that is driven by a motor, gear train, and associated wire such that the print head moves one line at a time over the stationary film unit.
In particular, to accomplish the advancement of the print head in Johnson, a worm gear is attached to the motor. The worm gear has worm gear teeth which are spaced such that an integral number, N of rotations of the worm gear corresponds to the distance between consecutive lines of the image, where N can be any integer greater than zero including one.
In mechanical communication with the worm gear is a drive gear. The drive gear is also in mechanical communication with the print head such that movement of the drive gear causes linear motion of the print head. The drive gear has drive gear teeth which interdigitate with the worm gear teeth such that rotation of the worm gear moves the print head by the predetermined amount, which, in turn, moves the print head by the distance between consecutive lines in the image.
The Johnson print head drive assembly advances a print head having static or rigid properties and thus is not susceptible to physical changes or deformations (such as twisting or bending) while it is advanced/driven/transported. While the print head drive assembly of Johnson is entirely satisfactory from a performance standpoint for driving a print head, it does not address the issues of driving a film medium as in the present invention.
Being that a film unit is flexible (compared to the prior art print head), there arises a need in the art for an effective system to drive the film unit past a stationary print head whereby the film unit can be accurately monitored and tracked for any changes or hesitations while it is advanced/driven.
Furthermore, the Johnson print head assembly would not be suited for a portable printing system as in the present invention. The relatively heavy weight of a print head (as opposed to a film unit) makes the print head more susceptible to shock, vibration, and gravitational orientation.
There arises a need in the art for accurately exposing advancing film in a portable printing system that is not susceptible to shock, vibration, and gravitational orientation.
Moreover, with regard to the Johnson print head assembly the transversal of the print head over the stationary film unit requires larger system volume than the present invention.
There arises a need in the art for accurately exposing advancing film in a portable printing system wherein the print head occupies minimal system volume.
Finally, the Johnson Print head assembly requires two motors (spread roller motor and drive gear motor), as opposed to only one motor of the present invention. The additional motor requires extra components and system volume as compared with the present invention. There arises a need in the art for accurately exposing advancing film in a printing system that minimizes the number of components so as to minimize system volume requirements and manufacturing costs.
It is stated in Takimoto, U.S. Pat. No. 5,032,911 entitled xe2x80x9cVideo Image Printer Using Liquid Crystal Light Valves and Primary Auxiliary Direction Scanningxe2x80x9d, and herein incorporated by reference, that a printer is coupled to a video camera wherein the film is exposed successively line by line, and is introduced between the squeezing rollers in synchronism with exposure of the film. The Takimoto patent further states that the squeezing rollers serve as a means for spreading processing solutions, and pressing the film there between, while at the same time feeding the film in the auxiliary scanning direction. The Takimoto patent fails to disclose how the feed or scan is accomplished so as to avoid defects in the film""s exposure.
Moreover, the Takimoto camera and printer are built as an integral unit and both must be carried into the field together whenever the camera is used even though the camera user may not actually desire hard copy prints in the field.
As disclosed in Finnelli et al., entitled xe2x80x9cElectronic Camera System with Detachable Printerxe2x80x9d, assigned to the same assignee as the present invention and herein incorporated by reference, an electronic imaging system comprises a camera and hard copy printer which can be interconnected for use either in combination or apart. While Finnelli imaging system is entirely satisfactory from a performance standpoint, it does not specifically disclose how the spread process is accomplished.
The primary objects of the present invention is to provide a compact and portable handheld imaging system comprising both an electronic camera and electronic photographic printer separately housed and readily interconnectable for selective use either together or apart; and wherein the film unit drive assembly is providing an accurate system of advancing or driving the film unit while the print head emits consecutive lines of the image data for exposing the film unit.
In particular, the print head is stationery while the film unit is advanced proximately thereto. Once the initial lines on the leading side of the film unit have been exposed then the processing fluid spread system begins to spread the processing fluid in a thin layer between the sheet elements, while the trailing portion of the film unit continues to be exposed. Since the advancing film unit is simultaneously exposed and processed, the processing fluid spread system may affect how smoothly the film unit is advanced. The ability for the film unit to be advanced at a relatively constant rate may be detrimentally affected by the forces created by the processing fluid spread system.
Also, since the present invention involves driving a film unit that has a flexible medium (unlike a rigid print head of the prior art), the film unit is vulnerable to being bent, twisted, or altered as it is advanced through the processing fluid spread system and the film unit drive assembly.
It also should be noted that the processing fluid spread system will need to restrict the liquid wave front, caused by the ruptured container (pod), from encroaching on the line of exposure provided by the stationary print head on the advancing film unit. Thus, the permitted shape and extent (down stream) of the wave front for the fluid processing aspect is significantly less than for the allowable wave front of the prior art.
There is therefore a need in the art for an effective method of driving the film unit so that it may be simultaneously exposed with high accuracy by a stationary print head and processed uniformly by the processing fluid spread system.
Thus, more primary concerns of the present invention involve providing a compact and portable handheld imaging system comprising an electronic camera and electronic printer useable either apart or in connection with respect to each other wherein the printer can provide a high quality photographic print of the image recorded in the camera; wherein the stationary print head effects progressive exposure on the advancing film unit simultaneously as the fluid spread system spreads the processing fluid over the film unit to effect processing of exposed portions of the film unit.
In particular, a need remains for a film unit drive assembly which can minimize the mechanical errors and the film medium deformations and interferences or hesitations imparted by the drive assembly system itself, as well as imparted by the fluid processing spread system. Also, the need arises to be able to monitor the position of the advancing film unit in light of any residual mechanical errors and the film media deformations and interferences that may still persist.
Of course, the above objectives and concerns need to be addressed in an imaging system that would be suitable for portability wherein the system weight is minimal and the system is not susceptible to shock, vibration, and gravitational orientation while in the operating or non-operating modes.
The present invention is directed generally toward an electronic photographic printer having a film unit drive assembly that advances the film unit (self-developing type) past a stationary print head for emitting consecutive lines of image data on the film unit to effect progressive exposure on the film unit simultaneously as a fluid spread system spreads the processing fluid over the film unit to effect processing of exposed portions of the film unit.
The present invention is directed generally towards a portable imaging system comprising an electronic camera for capturing images, disposed in a camera housing of a size that is conveniently carried by hand. The imaging system further comprising an electronic printer disposed in a printer housing also of a size that is conveniently carried by hand and that is distinct and detachable from the camera housing. The printer includes a film unit drive system and a stationary print head suitable for emitting consecutive lines of an image data on a self-processable film unit to expose the film unit at its image forming area, wherein the lines exposed on the film unit are separated by a predetermined distance, and wherein said exposure occurs while said film unit is being advanced along a transfer path proximately to the print head. The imaging system further comprises a complementary releasable connecting means operatively associated with respect to the camera housing and the printer housing for effecting a releasable fixed connection between the camera housing and the printer housing, the fixed connection also operates to effect an electrical connection between the camera, film unit drive system, and the printer. Also, a memory storage means is provided for storing the image data for each of the camera and the printer. In addition, a microprocessor unit is included having portions disposed respectively within the camera housing and the printer housing. The microprocessor being responsive to user selection for acquiring image data via the camera. The microprocessor is also operable to process the image data for memory storage and film unit exposure and processing.
In particular, the film unit drive system further comprises a motor mounted to the housing. Also included is a pair of transfer rollers comprising a driven transfer roller and a follower transfer roller to provide a transfer nip for advancing the film unit along a transfer path between the pair of transfer rollers. The driven transfer roller has a circumferential speed as effected by the speed of the motor, and the follower transfer roller has a circumferential speed as determined by the speed of the film unit being advanced between the transfer rollers along the transfer path. Also included is a pair of spread rollers comprising an upper roller and lower roller to provide a spread nip for receiving the leading edge of the film unit received from the transfer rollers and for feeding the film unit between the pair of spread rollers to continue the advancement of the film unit along the transfer path, and wherein the spread rollers having circumferential speed as effected by the speed of the motor. Further yet, a gear train is included that couples the motor to at least one of the spread rollers and to the driven transfer roller for transmitting power from the motor to at least one of the spread rollers and to the driven transfer roller to cause the spread rollers and transfer rollers to rotate and advance the film unit along the transfer path. Further included is a drive motor encoder in communication with the motor to control the motor speed so as to effect the circumferential speed of the driven transfer roller and the spread rollers. A film follower encoder is in communication with the follower transfer roller to measure the circumferential movement of the follower transfer roller, as determined by the speed of the film unit being advanced between the transfer rollers, whereby the circumferential movement of the follower transfer roller corresponds with the advancement of the film unit whereby its position respective to the print head can be determined. Finally, the print head is proximally located to the transfer rollers whereby once the leading edge of the film unit advances from the transfer rollers along the transfer path and engages the spread nip of the spread rollers the image forming area of the film unit is then exposed by the print head, wherein the print head emits consecutive lines of image data on the image forming area while the film unit continues to advance, and wherein the exposed lines on the film are separated by the predetermined distance.
An advantage of the present invention is that it provides a readily portable imaging system for use in the field and, more particularly, to an electronic camera and electronic printer housed and readily connectable with respect to each other in the field, and wherein the electronic printer comprises a film unit drive assembly that advances the film unit (self-developing type) past a stationary print head that emits consecutive lines of image data on the film unit to effect progressive exposure on the film unit simultaneously as a fluid spread system spreads the processing fluid over the film unit to effect processing of exposed portions of the film unit.
Another advantage of the present invention film unit drive assembly is that it provides an accurate system of advancing or driving the film unit while the print head emits consecutive lines of the image data for accurately exposing the film unit, with regular spacing of at least 1 xcexcm center-to-center spacing.
A further advantage of the present film unit drive assembly is that it can minimize the mechanical errors and the film medium deformations and interferences or hesitations imparted by the drive assembly system itself, as well as imparted by the fluid processing spread system.
Additionally, another advantage of the present invention is that it provides a compact and portable handheld imaging system comprising both an electronic camera and electronic photographic printer separately housed and readily interconnectable for selective use either together or apart.
Still further, another advantage of the present invention is that it is able to monitor the position of the advancing film unit in light of any residual mechanical errors and the film media deformations and interferences that may still persist.
Moreover, another advantage of the present invention is that LEDs in cooperation with a Spatial Light Modulator (SLM) of a print head provides the image data obtained by the image capture device. Also, the data of the relative location of the film unit with respect to the position of the print head is also determined. This also allows the print head to find the accurate location of the line spaces on the film unit for exposure, whereby the print head configuration and control system provide the means to register all three colors (R, G, B) of a line on top of each other with such high accuracy so as to avoid any kind of impulse artifacts that typically would have been associated with line-to-line spacing errors of prior art devices.
Still yet, another advantage of the present invention is that it is efficient in size and power requirements since the processing and exposing is simultaneously combined during operation. As a result, the system is also cost effective to manufacture. Finally, the system is readily portable for the user to carry.
Thus, an advantage of the present invention is that it provides a compact and portable handheld imaging system comprising an electronic camera and electronic printer useable either apart or in connection with respect to each other wherein the printer can provide a high quality photographic print of the image recorded in the camera; wherein the stationary print head effects progressive exposure on the advancing film unit simultaneously as the fluid spread system spreads the processing fluid over the film unit to effect processing of exposed portions of the film unit.
These and other objects, along with advantages and features of the invention disclosed herein, will be made more apparent from the description, drawings and claims that follow.